As requirements for data storage density increase for magnetic media, cell size decreases. A commensurate decrease in the size of a write element is difficult because in many systems, a strong write field gradient is needed to shift the polarity of cells on a magnetized medium. As a result, writing data to smaller cells on the magnetized medium using the relatively larger write pole may affect the polarization of adjacent cells (e.g., overwriting the adjacent cells). One technique for adapting the magnetic medium to utilize smaller cells while preventing adjacent data from being overwritten during a write operation is shingled magnetic recording (SMR).
SMR utilizes a write pole that generates a write field strong enough to affect two or more adjacent tracks at a time. To avoid data loss due to incidental track overwrites, data is managed in groups of tracks referred to as “data bands,” which are separated from one another by isolation regions that do not store any data. SMR systems typically re-write a group of data tracks whenever one or more data cells within the group are changed. For example, updating a single cell in track may entail writing all or a portion of an associated data band into memory (e.g., a scratchpad), updating the single cell, and re-writing the data band or portion of the data band back to original locations on the storage media. This processing overhead contributes to read/write latencies and reduces drive performance.